Generally, in a packet transfer network system, the transfer frequency of frames transferred between a transmission source packet transfer apparatus and a destination packet transfer apparatus is counted, and a route is assigned in accordance with the transfer frequency. With this traffic engineering technique, the traffic carrying efficiency is increased. In the conventional traffic engineering technique, to reduce the transfer load and path management load on the packet transfer apparatus and increase the transfer quality of the network, the frame transfer frequency is counted by a frame transfer apparatus which connects all packet transfer apparatuses and the route between the packet transfer apparatuses is reassigned in accordance with the traffic load of the frame transfer apparatus. With this method, the packet transfer apparatus can distribute the traffic load without monitoring the frame transfer frequency. The frame transfer apparatus has a table in which the addresses between all packet transfer apparatuses are recorded to count the frame transfer frequency between all the packet transfer apparatuses. The entry of this table is provisionally set by the operator (e.g., references 1, 2, 3, 4, and 5 to be described later).
Conventionally, a technique is known, which builds a logical connectionless packet transfer network in which a router exchanges packets by using IP on a connection network such as a photonic network including a wavelength path multiple link and wavelength path switching node. To transfer traffic in the network formed by this technique, routing of connection of the connection network and flow assignment of the connectionless packet transfer network to the connection need to be done.
The first prior art to execute such routing and flow assignment is GMPLS (Generalized Multi Protocol Label Switching) (e.g., references 6 and 7). For routing and flow assignment in GMPLS, first, connection routing of the connection network is permanently determined. After that, flow assignment of the connectionless packet transfer network for the determined connection is calculated.
The second prior art to execute such routing and flow assignment is a terabit-class super-network (e.g., references 1 and 2). For currently proposed routing and flow assignment in the terabit-class super-network, connection routing of the connection network and flow assignment of the connectionless packet transfer network for the connection are calculated simultaneously (e.g., references 4, 5, and 8 to be described later).
Conventionally, a technique is known, which builds a logical connectionless packet transfer network in which a router exchanges packets by using IP on a connection network such as a photonic network including a wavelength path multiple link and wavelength path switching node. To transfer traffic in the network formed by this technique, a wavelength path serving as connection of the connection network must be set.
A prior art for this is a terabit-class super-network. The terabit-class super-network includes a PE (Provider Edge) router which connects the terabit-class super-network and an external network outside it, an electric P (Provider) router which connects PEs by an IPv6 (Internet Protocol Version6) layer, and an optical P (Provider) router which connects the PE router and electric P router by a wavelength layer. Currently proposed connection setting in the terabit-class super-network is done by setting a wavelength path passing through the optical P router between the PE router, electric P router, and PE router and causing each router to transfer an IPv6 packet flowing on the wavelength path (references 1 and 2). In addition, a wavelength path which does not pass through the electric P router is also set between PE routers with a number of traffic requests (reference 8). FIG. 30 is a block diagram showing the arrangement of a conventional terabit-class super-network. Referring to FIG. 30, reference numeral 701 denotes a PE router; 702, an electric P router; 703, an optical P router; and 704, an external network connected to the PE router 701.
The above-described references will be described below.
[Reference 1] Junichi Murayama, Takeshi Yagi, Takahiro Tsujimoto, Toshiyuki Sakurai, Kenichi Matsui, Junichi Sumimoto, Masaki Kaneda, Kazuhiro Matsuda, and Hiroshi Ishii, “Development of Tera-bit Super Network (TSN) Technoloajes”, IEICE General Conference, 2003, B-7-81, March 2003.
[Reference 2] Junichi Murayama, Takahiro Tsujimoto, Kenichi Matsui, Kazuhiro Matsuda, and Hiroshi Ishii, “Traffic-Driven Optical IP Networking Architecture”, IEICE Transactions on Communications, Vol. E86-B, NO. 8, p. 2294-2301, August 2003.
[Reference 3] Takahiro Tsujimoto, Takeshi Yagi, Junichi Murayama, Kazuhiro Matsuda, and Hiroshi Ishii, “Evaluation of Optical Cut-Through Schemes in TSN”, IEICE General Conference, 2003, B-7-82, March 2003.
[Reference 4] Kenichi Matsui, Toshiyuki Sakurai, Masaki Kaneda, Junichi Murayama, and Hiroshi Ishii, A Study of Multi-Layer Traffic Enaineering for Tera-bit Super Network”, IEICE Technical Report, NS2002-316, IN2002-289, p. 297-302, March 2003.
[Reference 5] Matsui, Sakurai, Kaneda, Murayama, and Ishii, “A Multi-Layered Traffic Engineering Architecture for the Electronic/Optical Hybrid Network”, Communications, Computers and Signal Processing, 2003. PACRIM. 2003 IEEE Pacific Rim Conference on Publication, Vol. 1, p. 293-296, August 2003.
[Reference 6] E. Rosen et al, “Multiprotocol Label Switching Architecture”, RFC3031, Internet Engineering Task Force: IETF, January 2001.
[Reference 7] E. Mannie, “Generalized Multi-Protocol Label Switching (GMPLS) Architecture”, Internet Engineering Task Force: IETF, Internet Draft, draft-irft-ccamp-gmpls-architecture-07.txt, May 2003.
[Reference 8] Kenichi Matsui, Toshiyuki Sakurai, Masaki Kaneda, Junichi Murayama, and Hiroshi Ishii, Design of a cut-through optical path allocation scheme for TSN”, IEICE General Conference, 2003, B-7-84, March 2003.